LCoS（硅基液晶）显示器设计
摘要
本篇论文研究设计了一类硅基液晶(Liquid Crystal on Silicon,简称LCoS)显示器,其中主要涉及到两款不同用途的LCoS 显示芯片研制。LCoS 显示器是一种“夹心结构”——单晶硅基底片和镀有ITO 膜的玻璃片“夹”(封装)一层液晶材料。我们把视频转换电路、行扫描驱动电路和象素矩阵制作在硅基底上,而ITO 膜用作公共电极,液晶材料则工作在固定频率的交流信号下(场反转模式)。LCoS 设计成快速响应光阀,通过调制每个象素对入射光(来自时序光源)的反射程度(灰度)实现图像显示。
实际上,LCoS 显示技术是硅半导体平面技术与平板显示技术发展到相对成熟阶段相结合而诞生,因而具有了VLSI 技术的全部设计特征,然而就其功能与应用领域而言,LCoS 显示器仍是显示市场的一个产品。
本篇论文的研究工作不仅仅是局限于设计出两款可实现的LCoS 显示芯片(其中一款已在首钢日电成功流片,并封装成液晶盒实现了视频图像显示),更重要的是使人们能够对LCoS 电路设计、版图设计、相关制作工艺和系统设计有足够的了解。论文大致可分为四个部分。
第一部分(第1、2 章)阐明本篇论文的立题意义,综述液晶平板显示器应具备的基本性能。第二部分(第3、4 章)是本篇论文研究工作的理论基础,其间全面概述了目前系统芯片(SoC)物理设计方法,涉及到各种设计流程、工艺流程、EDA 辅助设计软件等,还介绍了具体的数模混合基本电路单元。第三部分(第5、6、7 章)基于前面对液晶显示器的认识,对SoC 物理设计方法的掌握,并结合已具备的数模混合电路经验,系统论述并设计了两款LCoS 显示器,一款是可用于近眼显示系统的场序彩色化微型LCoS 显示器,另一款是可用于投影显示系统的单色LCoS 显示器,该单色LCoS 显示芯片已成功流片,论文中将给出芯片实物照片、光学性能实测结果和所显示的视频图像。第四部分(第8、9 章)概述了LCoS 显示器制造工艺,总结了本篇论文的设计要点,而且对论文工作进行深层次的挖掘,尝试着提出建立硅基显示芯片的IP 模块,并探讨相应的设计方法。
本篇论文主要创新点有四个方面:
(1) 不连续场序光脉冲彩色模式设计。
(2) 低功耗数模转换器设计。
(3) 公共电极场反转低压驱动液晶显示设计。
(4) 建立硅基液晶显示芯片的IP 重用设计模块。
另外,本篇论文还有一个独到之处,即论文中相关的研究工作没有仅仅停留在理论研究和计算机辅助设计,而是进一步把研究工作实物化,根据实际CMOS 生产线的工艺要求,设计了一类用于投影显示系统的单色LCoS 显示芯片,并付诸生产流片,论文中给出相应生产出的芯片实物照片和光学性能实测结果。
In this thesis, a kind of Liquid Crystal on Silicon (LCoS) display is researched and designed. In fact, the LCoS microdisplay is fundamentally extremely small, active matrix liquid crystal display devices, which operate in a reflective mode. The active matrix is fabricated on a silicon chip using CMOS technology. The LCoS display that we design is small, less than an inch diagonal. The active matrix circuit provides a voltage between an electrode at each pixel and a common, transparent electrode, which is separated from the pixel electrodes by a thin layer of liquid crystal. The pixel electrode also acts as a reflective mirror. Light incident on the device through the transparent electrode is modulated by the liquid crystal electro-optics in response to the voltage applied to each pixel electrode. The reflected image is optically separated form the incident light and magnified for projection onto a screen or on the retina of the viewer.
The silicon active matrix backplane, LCoS display chip, of the device affords great flexibility in circuit design. The pixel size is generally not limited by the ability of the silicon technology to fabricate small devices. Rather, the ability of the optical system to efficiently illuminate the array and the lest physical size for the electric field of liquid crystal put a lower limit on the pixel size. Integration of row and column drivers in steadily accomplished by the basic CMOS capability of the silicon backplane; integration of additional functions is an available design choice.
Well, LCoS display technology is born after the semiconductor process technology and the flat plane display have been developing to the relative mature state and combine each other. As a result, LCoS has the same characteristics for design as the LVSI technique. However, from the view of function and application range, LCoS display still is one of production of the display market.
The goal for this thesis is not limited to design out two kinds of realizable LCoS display chip (one of LCoS designing has been realized in ShouGang-NEC Electronics Co., LTD.), it is the more important to make it understood that the main problem on LCoS circuit design, physical layout design, LCoS processes and LCoS system design. In fact, when we grasp the spirit of the LCoS design, it is easy to design the more kinds of LCoS chip.
Approximately, the thesis could be divided into four parts. In the first part, including chapter 1, 2, why select this topic to research and what is the infection of this research are
clarified. At same time the basic functions, which Liquid Crystal FPD must have, are stated. The second part, including chapter 2,3, is the basic theory of this thesis, which would direct the research. In this part,the popular SoC (System on Chip) physical design methods are summarized, as well as many design flows, processes and EDA software are introduced. On another way, the basic digital-analog mixed circuit cells are discussed. In the third part, including chapter 5,6,7, base on understanding with liquid crystal devices, grasping with SoC design methods, combining with experience on digital-analog mixed circuit, two kits of LCoS display chip are designed and discourse upon. Well, one kit is able to configure with near to eye microdisplay, which is frame sequential colorization. Another is able to configure with projector, which is made up of three mono-color LCoS display. And the LCoS chip used in projector has been fabricating in semiconductor factory. Moreover, the photographs of the chip and electronics parameter would be shown in the thesis. In the forth part, including chapter 8,9, fabricating process for LCoS display are summarized, and make the conclusion of design essentials. Moreover, bringing forward to set up IP modules for display on chip, and discuss the relative methods. There are four innovative keys in this thesis: (1) Design of the Incontinuous Luminance Pulse for the Frame Sequential Color Display. (2) Design for the low power Digital-Analog conversion. (3) Design for driving Liquid Crystal in the low voltage with common electronic field inversion. (4) Setting up IP reuse modules for Liquid Crystal on Silicon display chip. In addition, there is an unconventional change in this thesis, which is the research on the LCoS display chip would be not only limited in probing theory and electronic design assistance, but also realize in the semiconductor engine by the CMOS process standard. Change a word, a sort of mono-color LCoS display chip for projector would be fabricating in the foundry. And the photographs of the chip and optical characteristics would be shown in the thesis.
实际上,LCoS 显示技术是硅半导体平面技术与平板显示技术发展到相对成熟阶段相结合而诞生,因而具有了VLSI 技术的全部设计特征,然而就其功能与应用领域而言,LCoS 显示器仍是显示市场的一个产品。
本篇论文的研究工作不仅仅是局限于设计出两款可实现的LCoS 显示芯片(其中一款已在首钢日电成功流片,并封装成液晶盒实现了视频图像显示),更重要的是使人们能够对LCoS 电路设计、版图设计、相关制作工艺和系统设计有足够的了解。论文大致可分为四个部分。
第一部分(第1、2 章)阐明本篇论文的立题意义,综述液晶平板显示器应具备的基本性能。第二部分(第3、4 章)是本篇论文研究工作的理论基础,其间全面概述了目前系统芯片(SoC)物理设计方法,涉及到各种设计流程、工艺流程、EDA 辅助设计软件等,还介绍了具体的数模混合基本电路单元。第三部分(第5、6、7 章)基于前面对液晶显示器的认识,对SoC 物理设计方法的掌握,并结合已具备的数模混合电路经验,系统论述并设计了两款LCoS 显示器,一款是可用于近眼显示系统的场序彩色化微型LCoS 显示器,另一款是可用于投影显示系统的单色LCoS 显示器,该单色LCoS 显示芯片已成功流片,论文中将给出芯片实物照片、光学性能实测结果和所显示的视频图像。第四部分(第8、9 章)概述了LCoS 显示器制造工艺,总结了本篇论文的设计要点,而且对论文工作进行深层次的挖掘,尝试着提出建立硅基显示芯片的IP 模块,并探讨相应的设计方法。
本篇论文主要创新点有四个方面:
(1) 不连续场序光脉冲彩色模式设计。
(2) 低功耗数模转换器设计。
(3) 公共电极场反转低压驱动液晶显示设计。
(4) 建立硅基液晶显示芯片的IP 重用设计模块。
另外,本篇论文还有一个独到之处,即论文中相关的研究工作没有仅仅停留在理论研究和计算机辅助设计,而是进一步把研究工作实物化,根据实际CMOS 生产线的工艺要求,设计了一类用于投影显示系统的单色LCoS 显示芯片,并付诸生产流片,论文中给出相应生产出的芯片实物照片和光学性能实测结果。
In this thesis, a kind of Liquid Crystal on Silicon (LCoS) display is researched and designed. In fact, the LCoS microdisplay is fundamentally extremely small, active matrix liquid crystal display devices, which operate in a reflective mode. The active matrix is fabricated on a silicon chip using CMOS technology. The LCoS display that we design is small, less than an inch diagonal. The active matrix circuit provides a voltage between an electrode at each pixel and a common, transparent electrode, which is separated from the pixel electrodes by a thin layer of liquid crystal. The pixel electrode also acts as a reflective mirror. Light incident on the device through the transparent electrode is modulated by the liquid crystal electro-optics in response to the voltage applied to each pixel electrode. The reflected image is optically separated form the incident light and magnified for projection onto a screen or on the retina of the viewer.
The silicon active matrix backplane, LCoS display chip, of the device affords great flexibility in circuit design. The pixel size is generally not limited by the ability of the silicon technology to fabricate small devices. Rather, the ability of the optical system to efficiently illuminate the array and the lest physical size for the electric field of liquid crystal put a lower limit on the pixel size. Integration of row and column drivers in steadily accomplished by the basic CMOS capability of the silicon backplane; integration of additional functions is an available design choice.
Well, LCoS display technology is born after the semiconductor process technology and the flat plane display have been developing to the relative mature state and combine each other. As a result, LCoS has the same characteristics for design as the LVSI technique. However, from the view of function and application range, LCoS display still is one of production of the display market.
The goal for this thesis is not limited to design out two kinds of realizable LCoS display chip (one of LCoS designing has been realized in ShouGang-NEC Electronics Co., LTD.), it is the more important to make it understood that the main problem on LCoS circuit design, physical layout design, LCoS processes and LCoS system design. In fact, when we grasp the spirit of the LCoS design, it is easy to design the more kinds of LCoS chip.
Approximately, the thesis could be divided into four parts. In the first part, including chapter 1, 2, why select this topic to research and what is the infection of this research are
clarified. At same time the basic functions, which Liquid Crystal FPD must have, are stated. The second part, including chapter 2,3, is the basic theory of this thesis, which would direct the research. In this part,the popular SoC (System on Chip) physical design methods are summarized, as well as many design flows, processes and EDA software are introduced. On another way, the basic digital-analog mixed circuit cells are discussed. In the third part, including chapter 5,6,7, base on understanding with liquid crystal devices, grasping with SoC design methods, combining with experience on digital-analog mixed circuit, two kits of LCoS display chip are designed and discourse upon. Well, one kit is able to configure with near to eye microdisplay, which is frame sequential colorization. Another is able to configure with projector, which is made up of three mono-color LCoS display. And the LCoS chip used in projector has been fabricating in semiconductor factory. Moreover, the photographs of the chip and electronics parameter would be shown in the thesis. In the forth part, including chapter 8,9, fabricating process for LCoS display are summarized, and make the conclusion of design essentials. Moreover, bringing forward to set up IP modules for display on chip, and discuss the relative methods. There are four innovative keys in this thesis: (1) Design of the Incontinuous Luminance Pulse for the Frame Sequential Color Display. (2) Design for the low power Digital-Analog conversion. (3) Design for driving Liquid Crystal in the low voltage with common electronic field inversion. (4) Setting up IP reuse modules for Liquid Crystal on Silicon display chip. In addition, there is an unconventional change in this thesis, which is the research on the LCoS display chip would be not only limited in probing theory and electronic design assistance, but also realize in the semiconductor engine by the CMOS process standard. Change a word, a sort of mono-color LCoS display chip for projector would be fabricating in the foundry. And the photographs of the chip and optical characteristics would be shown in the thesis.
引文
[1.1] Robert L.Melcher. LCoS-Microdisplay Technology and Applications [J], Information Display, 2000, 16(7): 20～23
[1.2] [日本]金子英二著,刘维民,田辉译. 液晶电视显示技术[M], 江苏科学技术出版社,无锡,1990:231～241
[1.3] Sato F,Yagi Y,Hanihara H.High. Resolution and Bright LCD Projector with Reflective LCD Panels [C], SID International Symposium Digest of Technical, Papers XXVIII, Boston, 1997: 997-1000
[1.4] Cacharelis P,Kim U,Frazee J,Moore P,Brown K,Littrell R,Renteln P,Flack R. An 0.8 micron EEPROM Technology Modified for a Reflective PDLC Light-Valve Application [C], SID International Symposium Digest of Technical, Papers XXVIII, Boston, 1997: 289-292
[1.5] Paul M. Alt. Single Crystal Silicon for High Resolution Displays [C], Conference Record of the 1997 International Display Research Conference (SID, Toronto), 1997: M19-M28
[1.6] Michael Stefanov. Manufacturing LCoS Microdisplays [J], Information Display, 2000, 16(7): 24～26
[1.7] Chris Chinnock. Microdisplays and Manufacturing Infrastructure Mature at SID2000 [J], Information Display, 2000, 16(9): 18-21
[1.8] Chris Chinnock. Microdisplays and Their Applications [J], Information Display, 2001, 17(10): 22～25
[1.2] [日本]金子英二著,刘维民,田辉译. 液晶电视显示技术[M], 江苏科学技术出版社,无锡,1990:231～241
[1.3] Sato F,Yagi Y,Hanihara H.High. Resolution and Bright LCD Projector with Reflective LCD Panels [C], SID International Symposium Digest of Technical, Papers XXVIII, Boston, 1997: 997-1000
[1.4] Cacharelis P,Kim U,Frazee J,Moore P,Brown K,Littrell R,Renteln P,Flack R. An 0.8 micron EEPROM Technology Modified for a Reflective PDLC Light-Valve Application [C], SID International Symposium Digest of Technical, Papers XXVIII, Boston, 1997: 289-292
[1.5] Paul M. Alt. Single Crystal Silicon for High Resolution Displays [C], Conference Record of the 1997 International Display Research Conference (SID, Toronto), 1997: M19-M28
[1.6] Michael Stefanov. Manufacturing LCoS Microdisplays [J], Information Display, 2000, 16(7): 24～26
[1.7] Chris Chinnock. Microdisplays and Manufacturing Infrastructure Mature at SID2000 [J], Information Display, 2000, 16(9): 18-21
[1.8] Chris Chinnock. Microdisplays and Their Applications [J], Information Display, 2001, 17(10): 22～25